Industrial Internet of Things (IIoT) is a recent trend in the industry which aims to incorporate IoT technologies so as to increase efficiency and reduce costs of industrial processes. One of the vectors of this trend is the integration of Information and Communication Technologies (ICT) to modernize industrial communication systems and provide gains in scalability, flexibility, deployment and maintenance costs, as well as to support new services and applications.
Despite the relevant gains envisaged by its adoption, currently ICT do not offer adequate Quality-of-Service (QoS) for industrial applications.
In particular, Ethernet, which is the most common technology employed in ICT, lacks guaranteed traffic timeliness and efficient fault-tolerance mechanisms. To tackle these issues, several Ethernet-based real-time protocols were developed. Despite the important timeliness gains brought by these protocols, most of them are either incompatible with standard Ethernet systems or lack the adaptability and flexible resource management demanded by IIoT systems. However, the Hard Real-Time Ethernet Switching architecture (HaRTES) offers rather interesting properties, combining standard Ethernet compatibility with flexibility and strong real-time traffic management capabilities based on the Flexible Time-Triggered paradigm, characteristics that make this architecture suitable to support IIoT frameworks .
Software Defined Networking (SDN) is a centralized control, vendor agnostic, network design paradigm that offers improved, fine grained, management of network resources. There is a recent trend to merge SDN and IoT/IIoT, and potentially its qualities, in which the former may act as the open technology that manages the network platforms supporting the latter, helping to solve the current lack of interoperability in current IoT/IIoT platforms. Albeit its improved control over network resources, SDN emerged from the domain of campus networks and was subsequently adopted for data center networks, thus not providing adequate support for industrial real-time traffic.
